/* ==========================================================================
   BIOSAPIENCE.COM — DESIGN SYSTEM & STYLESHEET
   Inspired by National Geographic Editorial Design
   ========================================================================== */

:root {
  /* Brand Signature Colors */
  --natgeo-yellow: #FFCC00;
  --natgeo-yellow-hover: #E6B800;
  --natgeo-yellow-light: rgba(255, 204, 0, 0.12);
  
  /* Monochromes & Neutrals */
  --bg-dark: #0D0E11;
  --bg-dark-secondary: #16181D;
  --bg-dark-tertiary: #1E2127;
  --border-dark: #2B2F38;
  
  --bg-light: #FFFFFF;
  --bg-light-alt: #F7F8FA;
  --bg-light-card: #FFFFFF;
  --border-light: #E5E7EB;
  
  --text-dark-primary: #FFFFFF;
  --text-dark-secondary: #B0B5C0;
  --text-dark-muted: #7E8494;
  
  --text-light-primary: #121316;
  --text-light-secondary: #4A4F5C;
  --text-light-muted: #828896;

  /* Typography */
  --font-serif: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  
  /* Transitions & Shadows */
  --transition-smooth: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.16);
  --shadow-lg: 0 20px 48px rgba(0, 0, 0, 0.3);
}

/* Base Reset & Typography */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-dark);
  color: var(--text-dark-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition-smooth);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  outline: none;
}

/* Utility Containers */
.container {
  width: 100%;
  max-width: 1360px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-narrow {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ==========================================================================
   NAVIGATION (NatGeo Signature Header)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(13, 14, 17, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-dark);
  transition: var(--transition-smooth);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

/* Brand Logo with BioSapience Official Mark */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-site-logo {
  width: 38px;
  height: 38px;
  border-radius: 4px;
  object-fit: cover;
  display: inline-block;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.35);
  transition: var(--transition-smooth);
}

.brand-logo:hover .brand-site-logo {
  transform: scale(1.08);
  box-shadow: 0 4px 16px rgba(255, 204, 0, 0.45);
}

.brand-yellow-frame {
  display: none !important;
}

.brand-text {
  font-family: var(--font-sans);
  font-size: 1.35rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  color: #FFFFFF;
  text-transform: uppercase;
}

.brand-text span {
  color: var(--natgeo-yellow);
}

/* Nav Menu Links */
.nav-links {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 28px;
}

.nav-link {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #D4D7E0;
  position: relative;
  padding: 8px 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background-color: var(--natgeo-yellow);
  transition: width 0.3s ease;
}

.nav-link:hover, .nav-link.active {
  color: #FFFFFF;
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

/* Nav Actions (Search, Subscribe) */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.btn-icon {
  background: transparent;
  color: #FFFFFF;
  font-size: 1.1rem;
  padding: 8px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-smooth);
}

.btn-icon:hover {
  background-color: var(--bg-dark-tertiary);
  color: var(--natgeo-yellow);
}

.btn-subscribe {
  background-color: var(--natgeo-yellow);
  color: #000000;
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 8px 18px;
  border-radius: 2px;
  transition: var(--transition-smooth);
}

.btn-subscribe:hover {
  background-color: var(--natgeo-yellow-hover);
  box-shadow: 0 4px 14px rgba(255, 204, 0, 0.4);
}

.menu-toggle {
  display: none;
  background: transparent;
  color: #FFFFFF;
  font-size: 1.4rem;
  padding: 6px;
}

/* ==========================================================================
   HERO LEAD STORY (NatGeo Editorial Cover Feature)
   ========================================================================== */
.hero-feature {
  position: relative;
  width: 100%;
  min-height: 86vh;
  display: flex;
  align-items: flex-end;
  background-color: #000;
  overflow: hidden;
}

.hero-bg-media {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.hero-bg-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  filter: brightness(0.85);
  transform: scale(1.02);
  transition: transform 8s ease;
}

.hero-feature:hover .hero-bg-media img {
  transform: scale(1.06);
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    180deg,
    rgba(13, 14, 17, 0.2) 0%,
    rgba(13, 14, 17, 0.5) 50%,
    rgba(13, 14, 17, 0.95) 100%
  );
  z-index: 2;
}

.hero-content {
  position: relative;
  z-index: 3;
  width: 100%;
  padding: 60px 0 70px;
}

.hero-badge-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--natgeo-yellow);
  margin-bottom: 16px;
}

.hero-badge-kicker::before {
  content: '';
  display: inline-block;
  width: 12px;
  height: 3px;
  background-color: var(--natgeo-yellow);
}

.hero-headline {
  font-family: var(--font-serif);
  font-size: clamp(2.4rem, 4.8vw, 4.4rem);
  font-weight: 800;
  line-height: 1.1;
  color: #FFFFFF;
  max-width: 980px;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.5);
}

.hero-dek {
  font-size: clamp(1.05rem, 1.4vw, 1.3rem);
  line-height: 1.6;
  color: #D1D5DB;
  max-width: 820px;
  margin-bottom: 28px;
}

.hero-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 0.85rem;
  color: var(--text-dark-muted);
}

.hero-meta .author-byline {
  color: #FFFFFF;
  font-weight: 600;
}

.hero-meta .separator {
  color: var(--natgeo-yellow);
}

/* ==========================================================================
   LATEST STORIES TICKER & PROMO GRID
   ========================================================================== */
.section-latest-stories {
  padding: 60px 0;
  background-color: var(--bg-dark);
  border-bottom: 1px solid var(--border-dark);
}

.section-header-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--border-dark);
  padding-bottom: 16px;
}

.section-title-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.yellow-marker {
  width: 5px;
  height: 26px;
  background-color: var(--natgeo-yellow);
}

.section-title {
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #FFFFFF;
}

.view-all-link {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--natgeo-yellow);
  display: flex;
  align-items: center;
  gap: 6px;
}

.view-all-link:hover {
  color: #FFFFFF;
}

.promo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

.promo-card {
  display: flex;
  flex-direction: column;
  background: var(--bg-dark-secondary);
  border-radius: 2px;
  overflow: hidden;
  border: 1px solid var(--border-dark);
  transition: var(--transition-smooth);
}

.promo-card:hover {
  transform: translateY(-4px);
  border-color: #424754;
  box-shadow: var(--shadow-md);
}

.promo-thumb {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background-color: #111;
}

.promo-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s ease;
}

.promo-card:hover .promo-thumb img {
  transform: scale(1.08);
}

.promo-tag-pill {
  position: absolute;
  top: 12px;
  left: 12px;
  background-color: rgba(13, 14, 17, 0.85);
  backdrop-filter: blur(4px);
  color: var(--natgeo-yellow);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-left: 3px solid var(--natgeo-yellow);
}

.promo-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.promo-title {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.3;
  color: #FFFFFF;
  margin-bottom: 12px;
  transition: color 0.2s ease;
}

.promo-card:hover .promo-title {
  color: var(--natgeo-yellow);
}

.promo-snippet {
  font-size: 0.88rem;
  color: var(--text-dark-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
  flex-grow: 1;
}

.promo-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-dark-muted);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 12px;
}

/* ==========================================================================
   FEATURED EDITORIAL SPLIT (Big Lead + Companion Stack)
   ========================================================================== */
.editorial-split-section {
  padding: 80px 0;
  background-color: var(--bg-dark-secondary);
}

.split-layout {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 36px;
}

.lead-split-card {
  position: relative;
  background-color: var(--bg-dark);
  border: 1px solid var(--border-dark);
  border-radius: 2px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.lead-split-media {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
}

.lead-split-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.8s ease;
}

.lead-split-card:hover .lead-split-media img {
  transform: scale(1.05);
}

.lead-split-body {
  padding: 32px;
}

.lead-split-title {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.2;
  margin: 12px 0 16px;
  color: #FFFFFF;
}

.lead-split-card:hover .lead-split-title {
  color: var(--natgeo-yellow);
}

.lead-split-text {
  font-size: 1rem;
  color: var(--text-dark-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
}

/* Companion Stack */
.companion-stack {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.companion-card {
  display: flex;
  gap: 20px;
  background-color: var(--bg-dark);
  border: 1px solid var(--border-dark);
  padding: 16px;
  border-radius: 2px;
  transition: var(--transition-smooth);
}

.companion-card:hover {
  border-color: #444955;
  transform: translateX(4px);
}

.companion-media {
  flex-shrink: 0;
  width: 140px;
  height: 105px;
  overflow: hidden;
  border-radius: 2px;
}

.companion-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.companion-card:hover .companion-media img {
  transform: scale(1.1);
}

.companion-body {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.companion-kicker {
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--natgeo-yellow);
  margin-bottom: 6px;
}

.companion-title {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.35;
  color: #FFFFFF;
  margin-bottom: 8px;
}

.companion-card:hover .companion-title {
  color: var(--natgeo-yellow);
}

.companion-meta {
  font-size: 0.75rem;
  color: var(--text-dark-muted);
}

/* ==========================================================================
   CAROUSEL MODULE ("More from BioSapience")
   ========================================================================== */
.carousel-section {
  padding: 80px 0;
  background-color: var(--bg-dark);
  position: relative;
  overflow: hidden;
}

.carousel-controls {
  display: flex;
  gap: 10px;
}

.btn-carousel-arrow {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--bg-dark-tertiary);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  border: 1px solid var(--border-dark);
  transition: var(--transition-smooth);
}

.btn-carousel-arrow:hover {
  background: var(--natgeo-yellow);
  color: #000;
  border-color: var(--natgeo-yellow);
}

.carousel-track-container {
  overflow-x: auto;
  scroll-behavior: smooth;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding: 10px 0 20px;
}

.carousel-track-container::-webkit-scrollbar {
  display: none;
}

.carousel-track {
  display: flex;
  gap: 24px;
}

.carousel-card {
  flex: 0 0 320px;
  background: var(--bg-dark-secondary);
  border: 1px solid var(--border-dark);
  border-radius: 2px;
  overflow: hidden;
  transition: var(--transition-smooth);
}

.carousel-card:hover {
  transform: translateY(-6px);
  border-color: #4a505e;
}

.carousel-media {
  width: 100%;
  aspect-ratio: 3 / 2;
  overflow: hidden;
  position: relative;
}

.carousel-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s ease;
}

.carousel-card:hover .carousel-media img {
  transform: scale(1.08);
}

.carousel-body {
  padding: 20px;
}

.carousel-topic {
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--natgeo-yellow);
  margin-bottom: 8px;
}

.carousel-title {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.35;
  color: #FFFFFF;
}

.carousel-card:hover .carousel-title {
  color: var(--natgeo-yellow);
}

/* ==========================================================================
   PHOTO ESSAY / IMMERSIVE VISUAL DISPATCH (NatGeo Signature)
   ========================================================================== */
.visual-dispatch-section {
  padding: 100px 0;
  background: radial-gradient(circle at center, #181B22 0%, #08090A 100%);
  position: relative;
  border-top: 1px solid var(--border-dark);
  border-bottom: 1px solid var(--border-dark);
}

.visual-banner {
  text-align: center;
  max-width: 800px;
  margin: 0 auto 50px;
}

.visual-kicker {
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--natgeo-yellow);
  margin-bottom: 12px;
}

.visual-headline {
  font-family: var(--font-serif);
  font-size: clamp(2rem, 3.5vw, 3.2rem);
  font-weight: 800;
  color: #FFFFFF;
  margin-bottom: 16px;
}

.visual-desc {
  font-size: 1.1rem;
  color: var(--text-dark-secondary);
}

.photo-essay-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 24px;
}

.essay-item-large {
  grid-column: span 8;
  position: relative;
  aspect-ratio: 16 / 10;
  border-radius: 2px;
  overflow: hidden;
}

.essay-item-side {
  grid-column: span 4;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.essay-card-stacked {
  position: relative;
  height: calc(50% - 12px);
  border-radius: 2px;
  overflow: hidden;
}

.essay-photo {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.8s ease;
}

.essay-card:hover .essay-photo {
  transform: scale(1.06);
}

.essay-caption-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  padding: 30px;
  background: linear-gradient(180deg, transparent 0%, rgba(0, 0, 0, 0.9) 100%);
  color: #FFFFFF;
}

.essay-tag {
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--natgeo-yellow);
  margin-bottom: 6px;
}

.essay-caption-title {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 8px;
}

.essay-credit {
  font-size: 0.75rem;
  color: #9CA3AF;
  font-style: italic;
}

/* ==========================================================================
   MAGAZINE SPOTLIGHT (NatGeo Journal Yellow Frame Showcase)
   ========================================================================== */
.magazine-spotlight-section {
  padding: 90px 0;
  background-color: #0B0C0E;
  border-bottom: 1px solid var(--border-dark);
}

.magazine-container {
  display: grid;
  grid-template-columns: 1fr 1.3fr;
  align-items: center;
  gap: 60px;
}

.magazine-cover-wrapper {
  display: flex;
  justify-content: center;
  perspective: 1000px;
}

.magazine-cover-frame {
  position: relative;
  width: 340px;
  height: 480px;
  border: 14px solid var(--natgeo-yellow);
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.9), 0 0 30px rgba(255, 204, 0, 0.2);
  transform: rotateY(-6deg) rotateX(2deg);
  transition: transform 0.5s ease, box-shadow 0.5s ease;
  overflow: hidden;
  background-color: #000;
}

.magazine-cover-frame:hover {
  transform: rotateY(0deg) rotateX(0deg) scale(1.02);
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.95), 0 0 45px rgba(255, 204, 0, 0.4);
}

.magazine-cover-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.magazine-cover-masthead {
  position: absolute;
  top: 16px;
  left: 0;
  width: 100%;
  text-align: center;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 1.3rem;
  letter-spacing: 0.14em;
  color: #FFFFFF;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.8);
}

.magazine-cover-issue-tag {
  position: absolute;
  bottom: 24px;
  left: 20px;
  right: 20px;
  background: rgba(0, 0, 0, 0.85);
  padding: 16px;
  border-left: 4px solid var(--natgeo-yellow);
}

.magazine-cover-issue-tag h4 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  color: #FFF;
  line-height: 1.25;
}

.magazine-info-content h2 {
  font-family: var(--font-serif);
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1.15;
  color: #FFFFFF;
  margin-bottom: 20px;
}

.magazine-info-content p {
  font-size: 1.05rem;
  color: var(--text-dark-secondary);
  line-height: 1.7;
  margin-bottom: 28px;
}

.toc-list {
  list-style: none;
  margin-bottom: 36px;
}

.toc-item {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.95rem;
}

.toc-item-number {
  color: var(--natgeo-yellow);
  font-weight: 800;
  font-size: 0.85rem;
}

.magazine-action-buttons {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.btn-primary-yellow {
  background-color: var(--natgeo-yellow);
  color: #000000;
  font-weight: 800;
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 14px 28px;
  border-radius: 2px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition-smooth);
}

.btn-primary-yellow:hover {
  background-color: var(--natgeo-yellow-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 204, 0, 0.4);
}

.btn-secondary-outline {
  border: 1px solid var(--border-dark);
  color: #FFFFFF;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 14px 26px;
  border-radius: 2px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition-smooth);
}

.btn-secondary-outline:hover {
  border-color: #FFFFFF;
  background-color: rgba(255, 255, 255, 0.05);
}

/* ==========================================================================
   NEWSLETTER SIGNUP SECTION
   ========================================================================== */
.newsletter-section {
  padding: 80px 0;
  background: linear-gradient(135deg, #121419 0%, #1A1D24 100%);
  border-bottom: 1px solid var(--border-dark);
}

.newsletter-box {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  background: var(--bg-dark);
  border: 1px solid var(--border-dark);
  border-left: 6px solid var(--natgeo-yellow);
  padding: 48px;
  border-radius: 2px;
}

.newsletter-text h3 {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 800;
  color: #FFFFFF;
  margin-bottom: 10px;
}

.newsletter-text p {
  color: var(--text-dark-secondary);
  font-size: 1rem;
}

.newsletter-form {
  display: flex;
  gap: 12px;
  min-width: 420px;
}

.newsletter-input {
  flex-grow: 1;
  background-color: var(--bg-dark-secondary);
  border: 1px solid var(--border-dark);
  color: #FFFFFF;
  padding: 14px 18px;
  font-size: 0.95rem;
  border-radius: 2px;
  outline: none;
}

.newsletter-input:focus {
  border-color: var(--natgeo-yellow);
}

/* ==========================================================================
   FOOTER (NatGeo Comprehensive Editorial Footer)
   ========================================================================== */
.site-footer {
  background-color: #08080A;
  border-top: 1px solid var(--border-dark);
  padding: 80px 0 40px;
  color: var(--text-dark-secondary);
  font-size: 0.88rem;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1.2fr;
  gap: 48px;
  margin-bottom: 60px;
}

.footer-about {
  max-width: 320px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.footer-desc {
  line-height: 1.6;
  color: var(--text-dark-muted);
  margin-bottom: 24px;
}

.social-links {
  display: flex;
  gap: 14px;
}

.social-icon-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--bg-dark-secondary);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-dark);
  transition: var(--transition-smooth);
}

.social-icon-btn:hover {
  background-color: var(--natgeo-yellow);
  color: #000;
}

.footer-col-title {
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #FFFFFF;
  margin-bottom: 20px;
  position: relative;
}

.footer-col-title::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 20px;
  height: 2px;
  background-color: var(--natgeo-yellow);
}

.footer-menu {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-menu a {
  color: #9CA3AF;
  transition: color 0.2s ease;
}

.footer-menu a:hover {
  color: var(--natgeo-yellow);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
  color: var(--text-dark-muted);
  font-size: 0.78rem;
}

.footer-legal-links {
  display: flex;
  gap: 20px;
  list-style: none;
}

.footer-legal-links a:hover {
  color: #FFFFFF;
}

/* ==========================================================================
   ARTICLE PAGE STYLING (Longform Editorial NatGeo Feature)
   ========================================================================== */
.reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  background-color: var(--natgeo-yellow);
  z-index: 9999;
  width: 0%;
  transition: width 0.1s ease-out;
}

.article-hero {
  position: relative;
  width: 100%;
  min-height: 75vh;
  display: flex;
  align-items: flex-end;
  background-color: #000;
}

.article-header-container {
  padding: 60px 0;
  max-width: 960px;
  margin: 0 auto;
}

.article-headline {
  font-family: var(--font-serif);
  font-size: clamp(2.4rem, 4.2vw, 3.8rem);
  font-weight: 800;
  line-height: 1.15;
  color: #FFFFFF;
  margin: 16px 0 20px;
}

.article-deck {
  font-size: 1.3rem;
  line-height: 1.6;
  color: #D1D5DB;
  margin-bottom: 28px;
}

/* Audio Player Bar */
.audio-player-bar {
  background: var(--bg-dark-secondary);
  border: 1px solid var(--border-dark);
  border-left: 4px solid var(--natgeo-yellow);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin: 32px 0 48px;
  border-radius: 2px;
}

.audio-info {
  display: flex;
  align-items: center;
  gap: 14px;
}

.btn-play-audio {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--natgeo-yellow);
  color: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: transform 0.2s ease;
}

.btn-play-audio:hover {
  transform: scale(1.08);
}

.article-body-wrapper {
  background-color: #FCFCFD;
  color: #1A1D24;
  padding: 60px 0 90px;
}

.article-grid-layout {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 60px;
  align-items: start;
}

.article-content {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  line-height: 1.85;
  color: #242730;
}

.article-content p {
  margin-bottom: 30px;
}

.article-content p.lead-paragraph::first-letter {
  font-size: 5rem;
  line-height: 0.8;
  float: left;
  margin: 6px 14px 0 0;
  color: #000;
  font-family: var(--font-serif);
  font-weight: 900;
}

.article-content h2 {
  font-family: var(--font-sans);
  font-size: 1.8rem;
  font-weight: 800;
  color: #0F1116;
  margin: 48px 0 20px;
  letter-spacing: -0.01em;
}

.article-pullquote {
  border-top: 3px solid var(--natgeo-yellow);
  border-bottom: 3px solid var(--natgeo-yellow);
  padding: 32px 0;
  margin: 48px 0;
  font-family: var(--font-serif);
  font-size: 1.7rem;
  font-style: italic;
  line-height: 1.45;
  color: #0A0B0E;
  text-align: center;
}

.article-figure {
  margin: 44px 0;
}

.article-figure img {
  width: 100%;
  border-radius: 2px;
}

.article-figure figcaption {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  color: #646A78;
  margin-top: 10px;
  line-height: 1.5;
  border-left: 2px solid var(--natgeo-yellow);
  padding-left: 12px;
}

/* Article Sidebar */
.article-sidebar {
  position: sticky;
  top: 100px;
  display: flex;
  flex-direction: column;
  gap: 36px;
}

.author-card-box {
  background: #F1F3F7;
  padding: 24px;
  border-radius: 2px;
  border: 1px solid #E2E5EB;
}

.author-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}

.author-avatar {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--natgeo-yellow);
}

.author-card-box h4 {
  font-family: var(--font-sans);
  font-size: 1.05rem;
  font-weight: 800;
  color: #111;
}

.author-role {
  font-size: 0.8rem;
  color: #6B7280;
  text-transform: uppercase;
}

.author-bio {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  color: #4B5563;
  line-height: 1.5;
}

/* ==========================================================================
   SEARCH OVERLAY MODAL
   ========================================================================== */
.search-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(9, 10, 13, 0.95);
  backdrop-filter: blur(14px);
  z-index: 99999;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding-top: 120px;
}

.search-modal.active {
  display: flex;
}

.search-container {
  width: 100%;
  max-width: 780px;
  padding: 0 24px;
}

.search-header-bar {
  display: flex;
  align-items: center;
  border-bottom: 2px solid var(--natgeo-yellow);
  padding-bottom: 12px;
}

.search-input-field {
  width: 100%;
  background: transparent;
  border: none;
  font-family: var(--font-serif);
  font-size: 2rem;
  color: #FFFFFF;
  outline: none;
}

.btn-close-search {
  background: transparent;
  color: #FFF;
  font-size: 1.8rem;
}

/* ==========================================================================
   RESPONSIVE DESIGN (Tablets & Mobile)
   ========================================================================== */
@media (max-width: 1024px) {
  .nav-links {
    display: none;
  }
  .menu-toggle {
    display: block;
  }
  .split-layout {
    grid-template-columns: 1fr;
  }
  .magazine-container {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .magazine-action-buttons {
    justify-content: center;
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
  .article-grid-layout {
    grid-template-columns: 1fr;
  }
  .newsletter-box {
    flex-direction: column;
    text-align: center;
  }
  .newsletter-form {
    min-width: 100%;
    width: 100%;
  }
  .photo-essay-grid {
    grid-template-columns: 1fr;
  }
  .essay-item-large, .essay-item-side {
    grid-column: span 12;
  }
}

@media (max-width: 768px) {
  .hero-feature {
    min-height: 70vh;
  }
  .footer-top {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}

/* ==========================================================================
   DYNAMIC GRAPHICAL VISUALIZATIONS (National Geographic Interactive Suite)
   ========================================================================== */

.natgeo-viz-section {
  padding: 80px 0;
  background-color: var(--bg-dark-secondary);
  border-top: 1px solid var(--border-dark);
  border-bottom: 1px solid var(--border-dark);
  position: relative;
}

.natgeo-viz-container {
  background: #090A0D;
  border: 1px solid var(--border-dark);
  border-radius: 2px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
}

.natgeo-viz-container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 48px;
  height: 4px;
  background: var(--natgeo-yellow);
  z-index: 5;
}

.natgeo-viz-header {
  padding: 24px 30px;
  border-bottom: 1px solid var(--border-dark);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  background: rgba(18, 20, 26, 0.7);
  backdrop-filter: blur(8px);
}

.natgeo-viz-kicker {
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--natgeo-yellow);
  display: block;
  margin-bottom: 4px;
}

.natgeo-viz-title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  color: #FFFFFF;
  margin: 0;
}

.natgeo-viz-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 204, 0, 0.1);
  border: 1px solid rgba(255, 204, 0, 0.3);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--natgeo-yellow);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.natgeo-viz-badge .pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--natgeo-yellow);
  box-shadow: 0 0 10px var(--natgeo-yellow);
  animation: pulseGlow 1.8s infinite ease-in-out;
}

@keyframes pulseGlow {
  0%, 100% { opacity: 0.4; transform: scale(0.9); }
  50% { opacity: 1; transform: scale(1.2); }
}

/* Visualization Canvas & Interactive Workspace */
.natgeo-viz-workspace {
  position: relative;
  min-height: 460px;
  width: 100%;
  background: radial-gradient(circle at 50% 30%, #151821 0%, #07080A 100%);
  overflow: hidden;
}

.natgeo-viz-workspace canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* Grid overlay for technical NatGeo infographic look */
.tech-grid-bg {
  background-image: linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 32px 32px;
}

/* Timeline Eons Navigation */
.deep-time-nav {
  display: flex;
  overflow-x: auto;
  border-bottom: 1px solid var(--border-dark);
  background: #0E1015;
}

.eon-btn {
  padding: 14px 22px;
  background: transparent;
  color: var(--text-dark-secondary);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: none;
  border-bottom: 3px solid transparent;
  white-space: nowrap;
  transition: var(--transition-smooth);
}

.eon-btn:hover {
  color: #FFF;
  background: rgba(255, 255, 255, 0.02);
}

.eon-btn.active {
  color: #FFF;
  border-bottom-color: var(--natgeo-yellow);
  background: rgba(255, 204, 0, 0.05);
}

/* Interactive Oceanic Stratigraphy Depth Bar */
.ocean-strat-wrap {
  display: grid;
  grid-template-columns: 80px 1fr 340px;
  min-height: 520px;
  background: #06080D;
}

@media (max-width: 900px) {
  .ocean-strat-wrap {
    grid-template-columns: 60px 1fr;
  }
  .ocean-depth-sidebar {
    grid-column: span 2;
  }
}

.ocean-depth-gauge {
  background: #0B0E14;
  border-right: 1px solid var(--border-dark);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 24px 8px;
  font-size: 0.7rem;
  color: var(--text-dark-muted);
  font-family: monospace;
  text-align: center;
}

.ocean-gradient-stage {
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 30px;
  background: linear-gradient(180deg, #1B4965 0%, #0B2545 25%, #051622 55%, #020810 85%, #000307 100%);
  transition: all 0.5s ease;
}

.ocean-depth-sidebar {
  background: #0D0F14;
  border-left: 1px solid var(--border-dark);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.depth-slider-control {
  width: 100%;
  accent-color: var(--natgeo-yellow);
  cursor: pointer;
  margin: 16px 0;
}

/* Before / After Comparison Image Slider */
.natgeo-comparison-slider {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  max-height: 540px;
  overflow: hidden;
  user-select: none;
}

.comparison-before-img,
.comparison-after-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.comparison-after-img-wrap {
  position: absolute;
  top: 0;
  left: 0;
  width: 50%;
  height: 100%;
  overflow: hidden;
  border-right: 3px solid var(--natgeo-yellow);
  box-shadow: 0 0 16px rgba(0, 0, 0, 0.6);
}

.comparison-handle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--natgeo-yellow);
  color: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  font-size: 1.1rem;
  cursor: ew-resize;
  box-shadow: 0 0 20px rgba(255, 204, 0, 0.8);
  z-index: 10;
}

/* Micrographic Magnifying Loupe */
.loupe-container {
  position: relative;
  cursor: crosshair;
  overflow: hidden;
}

.loupe-lens {
  position: absolute;
  width: 160px;
  height: 160px;
  border: 3px solid var(--natgeo-yellow);
  border-radius: 50%;
  box-shadow: 0 0 25px rgba(255, 204, 0, 0.6), inset 0 0 15px rgba(0, 0, 0, 0.4);
  pointer-events: none;
  display: none;
  background-repeat: no-repeat;
  z-index: 30;
}

/* Interactive Genomic Architecture Strip */
.genome-strip {
  display: flex;
  width: 100%;
  height: 48px;
  border-radius: 2px;
  overflow: hidden;
  border: 1px solid var(--border-dark);
  margin: 20px 0;
}

.genome-segment {
  height: 100%;
  transition: opacity 0.2s ease, transform 0.2s ease;
  cursor: pointer;
  position: relative;
}

.genome-segment:hover {
  opacity: 0.9;
  filter: brightness(1.2);
}

.genome-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 14px;
  font-size: 0.8rem;
}

.genome-legend-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.genome-color-dot {
  width: 12px;
  height: 12px;
  border-radius: 2px;
}

/* Interactive Dialectic SVG Network */
.mindmap-node {
  cursor: pointer;
  transition: all 0.3s ease;
}

.mindmap-node:hover circle {
  stroke: var(--natgeo-yellow);
  stroke-width: 4px;
}

.mindmap-node text {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 700;
  fill: #FFFFFF;
  text-shadow: 0 2px 4px rgba(0,0,0,0.8);
}

.mindmap-link {
  stroke: rgba(255, 204, 0, 0.3);
  stroke-width: 2px;
  stroke-dasharray: 6 3;
  animation: dashStream 20s linear infinite;
}

@keyframes dashStream {
  to {
    stroke-dashoffset: -100;
  }
}

/* ==========================================================================
   NESTED PAGES & WORDPRESS DYNAMIC NAVIGATION STYLES
   ========================================================================== */

.primary-nav-wrapper {
  display: flex;
  align-items: center;
}

.nav-links {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 8px;
  margin: 0;
  padding: 0;
}

.nav-links li,
.nav-links .menu-item,
.nav-links .page_item {
  position: relative;
  list-style: none;
}

.nav-links li a,
.nav-links .menu-item a,
.nav-links .page_item a {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #D4D7E0;
  display: block;
  padding: 8px 14px;
  transition: var(--transition-smooth);
  text-decoration: none;
}

.nav-links li a:hover,
.nav-links li.current-menu-item > a,
.nav-links li.current_page_item > a,
.nav-links li.current-menu-ancestor > a,
.nav-links li.current_page_ancestor > a {
  color: #FFFFFF;
}

/* NatGeo Dropdown for Nested Pages Sub-menus */
.nav-links ul.sub-menu,
.nav-links ul.children {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 260px;
  background: #111318;
  border: 1px solid var(--border-dark);
  border-top: 2px solid var(--natgeo-yellow);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.6);
  list-style: none;
  padding: 6px 0;
  margin: 0;
  display: none;
  z-index: 1001;
  border-radius: 0 0 2px 2px;
}

.nav-links li:hover > ul.sub-menu,
.nav-links li:hover > ul.children {
  display: block;
}

/* Third-tier nested sub-menus */
.nav-links ul.sub-menu ul.sub-menu,
.nav-links ul.children ul.children {
  top: 0;
  left: 100%;
  border-top: 1px solid var(--border-dark);
  border-left: 2px solid var(--natgeo-yellow);
}

.nav-links ul.sub-menu li,
.nav-links ul.children li {
  width: 100%;
}

.nav-links ul.sub-menu li a,
.nav-links ul.children li a {
  padding: 10px 20px;
  font-size: 0.8rem;
  text-transform: none;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: #B0B5C0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.nav-links ul.sub-menu li a:hover,
.nav-links ul.children li a:hover {
  background: rgba(255, 204, 0, 0.08);
  color: var(--natgeo-yellow);
  padding-left: 24px;
}

/* ==========================================================================
   WATU QUIZ & INTERACTIVE EXAMINATION STYLING (National Geographic Theme)
   ========================================================================== */

.quiz-area, .watu_quiz, #watu_quiz {
  background: var(--bg-dark-secondary) !important;
  border: 1px solid var(--border-dark) !important;
  border-left: 5px solid var(--natgeo-yellow) !important;
  padding: 32px !important;
  border-radius: 2px !important;
  margin: 30px 0 !important;
  box-shadow: var(--shadow-md) !important;
}

.watu-question {
  background: #0F1116 !important;
  border: 1px solid var(--border-dark) !important;
  border-radius: 2px !important;
  padding: 24px !important;
  margin-bottom: 28px !important;
  transition: var(--transition-smooth) !important;
}

.watu-question:hover {
  border-color: rgba(255, 204, 0, 0.4) !important;
}

.watu-question .question-content p {
  font-family: var(--font-serif) !important;
  font-size: 1.25rem !important;
  color: #FFFFFF !important;
  font-weight: 700 !important;
  line-height: 1.4 !important;
  margin-bottom: 16px !important;
}

.watu_num {
  color: var(--natgeo-yellow) !important;
  font-weight: 800 !important;
  margin-right: 6px !important;
}

.watu-question-choice {
  padding: 12px 16px !important;
  margin: 8px 0 !important;
  background: #16181F !important;
  border: 1px solid var(--border-dark) !important;
  border-radius: 2px !important;
  display: flex !important;
  align-items: center !important;
  transition: var(--transition-smooth) !important;
  cursor: pointer !important;
}

.watu-question-choice:hover {
  border-color: var(--natgeo-yellow) !important;
  background: rgba(255, 204, 0, 0.05) !important;
}

.watu-question-choice input[type="radio"],
.watu-question-choice input[type="checkbox"] {
  accent-color: var(--natgeo-yellow) !important;
  width: 18px !important;
  height: 18px !important;
  margin-right: 12px !important;
}

.watu-question-choice label {
  color: #E2E8F0 !important;
  font-size: 0.95rem !important;
  cursor: pointer !important;
}

.watu-feedback {
  background: rgba(255, 204, 0, 0.08) !important;
  border-left: 3px solid var(--natgeo-yellow) !important;
  color: #E2E8F0 !important;
  padding: 16px 20px !important;
  border-radius: 2px !important;
  margin-top: 16px !important;
  font-size: 0.92rem !important;
  line-height: 1.6 !important;
}

.watu-submit-button,
input[type="button"].watu-submit-button,
input[type="submit"].watu-submit-button {
  background: var(--natgeo-yellow) !important;
  color: #000000 !important;
  font-weight: 800 !important;
  letter-spacing: 0.08em !important;
  text-transform: uppercase !important;
  font-size: 0.9rem !important;
  padding: 14px 32px !important;
  border: none !important;
  border-radius: 2px !important;
  cursor: pointer !important;
  transition: var(--transition-smooth) !important;
  margin-top: 20px !important;
}

.watu-submit-button:hover {
  background: var(--natgeo-yellow-hover) !important;
  transform: translateY(-2px) !important;
  box-shadow: 0 4px 14px rgba(255, 204, 0, 0.4) !important;
}

/* ==========================================================================
   ELEMENTOR HARMONIZATION
   ========================================================================== */

body.elementor-default {
  background-color: var(--bg-dark) !important;
}

.elementor-content-wrap {
  width: 100%;
}